1. Field of the Invention
The present invention relates to security documents, such as monetary, security or value related documents, wherein the dyes are applied to or embedded in the security document.
2. Description of the Related Art
The invention is based on a technology similar to that described, for example, in U.S. Pat. No. 4,738,901. In this references, a document has phosphor particles embedded therein as protection against copying. Copy protection is enabled, because the laser associated with the copier excites the phosphor particles and the radiation emitted by the phosphor particles is received by a second detector which indicates to the copier that the documents are protected. However, this copy protection process cannot check the authenticity of a security and sensitive document.